With the increase of data transmission capacity per second through the Internet, there has been an increased amount of multimedia data, including video and picture files, than the past, when simple text data had been mostly transmitted. Accordingly, there has been an increased demand for video compression technologies.
Unlike the method of compressing still images (e.g. photographs), the video compression method compresses a plurality of frames. Accordingly, the video compression method can compress videos by using certain relationships between frames. For example, the video compression method can acquire high compression ratio and high video quality by using the relationship between pixels corresponding to a plurality of frames.
The video compression method can also perform the compression more efficiently by using the frame-skipping technology, which performs the compression by skipping certain frames. The frame-skipping technology is divided into a fixed frame-skipping type and a variable frame-skipping type. The fixed frame-skipping type needs no complex pre-treating process. The fixed frame-skipping type, however, has some problems that the compression is performed by skipping important data frames or frames that are difficult to interpolate. The variable frame-skipping type has been developed to solve the problem. However, this variable frame-skipping type typically analyzes the whole video sequence. This has high complexity so that it is difficult to process videos in real time. The variable frame-skipping type also depends on the encoding technology.